A nozzle guide vane is a static segment of a gas turbine which guides gas exhausted from a combustor to a rotor blade located downstream the nozzle guide vane. The nozzle guide vane may be supported by a radially inner platform and by a radially outer platform. During operation of the gas turbine the nozzle guide vane as well as the platform supporting the nozzle guide vane may be subjected to a high temperature of the impinging gas exhausted from the combustor. In particular, the impinging gas may result in extensive oxidation of the material comprised in the platform for supporting the nozzle guide vane. Thereby, the operation lifetime of the platform may be limited.
In a conventional turbine the platform for supporting the nozzle guide vane may be manufactured with a thermal barrier coating to achieve longer lifetimes.
EP 1 674 661 discloses an internally cooled gas turbine engine turbine vane, wherein a cooling passage way is formed within the turbine vane.
U.S. Pat. No. 6,602,047 discloses an apparatus for cooling a gas turbine nozzle, wherein the nozzle comprises a first wall, a second wall and a plurality of pins extending there between. The nozzle also includes at least one row of turbulators.
EP 1 022 435 discloses an internal cooling circuit for a gas turbine bucket, wherein the internal cooling circuit has a serpentine configuration and includes rib segments.
U.S. Pat. No. 5,615,546 discloses an appliance for cooling a gas turbine combustion chamber, wherein connecting openings are arranged between adjacent cooling ducts.
There may be a need for a platform segment for supporting a nozzle guide vane for a gas turbine which has a longer lifetime compared to a conventional platform segment. Further, there may be a need for a platform segment for supporting a nozzle guide vane for a gas turbine which is less susceptible to impinging hot gas exhausted from a combustor compared to a conventional platform segment. Further, there may be a need for a nozzle guide vane arrangement for a gas turbine providing a longer operation lifetime compared to a conventional nozzle guide vane arrangement and providing also or alternatively less susceptibility to impinging or high temperature gas exhausted from a combustor.
Further, there may be a need for a method for cooling a nozzle guide vane platform segment, wherein the method is more effective and protects the nozzle guide vane platform segment in an improved way against high temperature impinging gas.